Key Facts About EOS

• Name: EOS, derived from Dewi Fajar Greece.
• type: Crescent-shaped hydrogen gas cloud.
• Distance: Approximately 300 light-years from earth, making it the closest molecular cloud discovered to date.
• Size: Spans about 100 light-years, equivalent to roughly 40 Earth-Moon distances lined up side by side.

The Finding

The discovery of EOS was somewhat accidental. Blakesley Burkhart, a professor at Rutgers University, stumbled upon the cloud while analyzing 20-year-old data from a spectrograph aboard the Korean Science and Technology satellite, launched in 2003. The satellite was designed to map hot gas distribution in the Milky Way.

That’s very coincidental. I see this data and see this structure. I am like,’Huh,I don’t know what it is. Something unique’.
Blakesley Burkhart, Rutgers University

Unlike typical molecular clouds, EOS has a low carbon monoxide (CO) content, which made it tough to detect using conventional methods. Instead, researchers identified EOS through fluorescence in its hydrogen molecules, a novel approach that could reveal many similar hidden clouds throughout the galaxies.

This cloud is very large, and has been hidden so far.
Blakesley Burkhart, Rutgers University

The findings were published April 28 in the journal *Nature Astronomy*.

Interaction with North Polar Spur

EOS’s crescent shape is a result of its interaction with the North Polar Spur, a large ionized gas region extending from the Milky Way to the North Sky Pole. the energy and radiation from the North Polar Spur, possibly driven by past supernova events or stellar winds, have influenced the surrounding gas, including EOS.

Simulations suggest that EOS will likely evaporate in about 6 million years due to the high-energy cosmic photons from the North Polar Spur and other sources tearing apart its molecular hydrogen reservoir.

Future Research

Follow-up studies are underway, utilizing data from the European Space Agency’s GAIA Space Telescope, to search for signs of recent or ongoing star formation within EOS. Initial findings suggest that the cloud has not experienced meaningful star formation in the past, but it remains uncertain whether it will begin forming stars before it dissipates.

This cloud is really shining in the dark.
Blakesley Burkhart, Rutgers University

Burkhart and her team are also developing a mission concept for a NASA spacecraft, tentatively named the EOS space telescope, to observe molecular hydrogen content in clouds throughout the Milky Way using distant ultraviolet wavelengths. This would help to carry out a census of molecular hydrogen gas formation and destruction.

Surely ther are more dark clouds CO who are waiting to be found.
Blakesley Burkhart, rutgers University

The discovery of EOS opens new avenues for understanding the distribution of hydrogen, the most abundant substance in the universe, and its role in star and planet formation.

There are still many questions that have not been answered. We just started.
Blakesley Burkhart, Rutgers University

FAQ About Molecular Clouds

What are molecular clouds?

Molecular clouds are regions in space where molecules, especially hydrogen (H2), are dense enough to form stars.

How far away is EOS?

EOS is approximately 300 light-years from Earth.

Why was EOS hard to detect?

EOS has a low carbon monoxide (CO) content, making it difficult to detect using conventional methods.

What is the North Polar Spur?

The North Polar Spur is a large ionized gas region that interacts with EOS, influencing its shape and evolution.

What’s next for EOS research?

Researchers plan to study EOS for star formation and are proposing a space telescope to study similar clouds.